This protocol is part of a proposal entitled "Immunotherapy targeting human breast cancer cells in vivo with immune-enhanced and educated autologous dendritic cells". With the long-term goal of utilizing immunotherapy for the treatment of breast cancer, it is proposed to use an animal model of human breast cancer to develop the methodology. This immunotherapy will focus on utilizing the unique capacity of autologous dendritic cells, potent antigen-presenting cells to enhance host immunosurveillance against breast cancer. This phase of the study involves generating dendritic cells from human peripheral CD34+ stem cells and harvesting them by means of apheresis.